Floating offshore drilling production facilities are typically moored to the seabed via multiple catenary mooring lines, taut leg mooring lines or vertical tethers to maintain the facility in the required position with respect to the seabed. Such mooring lines are typically paid out from the vessel and connected to the seabed pile or anchor; this connection is achieved remotely owing to the water depths operated in modern oilfields.
Due to the environmental and operational loading conditions, the mooring tether must be reliably connected to the structure and simultaneously accommodate fluctuating axial, torsional and angular motions occurring between the mooring line and vessel structure. These motions occur in response to loading from ocean currents, waves and wind. Similar duty may be required in a structural connector used for anchoring seabed structures or risers.
The combination of remote operation, high tension and angular motions leads to a challenging design scenario to prevent the components from being difficult to operate, overstressed or fatigued.
It is an aim of the present invention to overcome at least one of the problems associated with the prior art whether referred to herein or otherwise.